Premium
“Visible” Phase Separation of MAPbI 3 /δ‐FAPbI 3 Films for High‐Performance and Stable Photodetectors
Author(s) -
Shang Meijia,
Lian Gang,
Lv Song,
Zhu Fei,
Wang Qilong,
Cui Deliang,
Zheng Zhaoke,
Huang Baibiao
Publication year - 2021
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.202100266
Subject(s) - materials science , passivation , photocurrent , perovskite (structure) , photodetector , responsivity , formamidinium , phase (matter) , optoelectronics , iodide , carrier lifetime , chemical engineering , nanotechnology , layer (electronics) , inorganic chemistry , silicon , chemistry , organic chemistry , engineering
Simultaneous achievement of elevated photocurrent by increasing grain size of perovskite films and reduced dark current by introducing passivation phase as well as improved stability is significant and tough challenge for perovskite‐based photodetector devices. Herein, in‐situ formation of “visible” formamidinium lead iodide (δ‐FAPbI 3 ) phase within a high‐quality methylamine lead iodide (MAPbI 3 ) film is reported by a pressure‐induced phase separation strategy. The MAPbI 3 single‐crystal grains are adequately grown and parts of them are over 20 µm in lateral dimension. More importantly, the incursion of δ‐FAPbI 3 with high resistance behaves like an organic scaffold to passivate the trap state, limit cation diffusion, and increase intrinsic resistance of the MAPbI 3 film. Accordingly, the MAPbI 3 /δ‐FAPbI 3 photodetector devices exhibit excellent photoelectrical performance, including high detectivity, responsivity, and on/off ratio due to long carrier lifetime and low defect density. Furthermore, the unsealed MAPbI 3 /δ‐FAPbI 3 film device retains over 94% of its initial photocurrent after 15 days in ambient conditions, exhibiting significantly improved stability. The introduction of “useless” δ‐FAPbI 3 phase in high‐quality perovskite films opens up a new way toward improved photoelectrical performance and stability.